The goal of this protocol is to identify families with inherited movement disorders and evaluate disease manifestations to establish an accurate clinical diagnosis by using newest technological advances and investigate the underlying molecular mechanisms. Studies of inherited movement disorders in large families with good genealogical records are especially valuable. Patients with diseases of known molecular basis will be genotyped in order to investigate phenotype/genotype correlation. Patients with disease of unknown or incomplete genetic characterization will be studied with a hope of contributing to the identification of specific disease-causing genes and genetic mechanisms responsible for a specific disorder.